package datastructurs.binarysorttree;

public class BinarySortTreeUnit {
    public static void main(String[] args) {
        int[] arr = {7,3,10,12,5,1,9,2};
        BinarySortTree binarySortTree = new BinarySortTree();
        for(int i=0;i<arr.length;i++){
            binarySortTree.add(new Node(arr[i]));
        }
        System.out.println("中序遍历二叉排序树：");
        binarySortTree.infixOrder();
        System.out.println("删除节点后");
        binarySortTree.delNode(2);
        binarySortTree.infixOrder();
    }

}
class BinarySortTree{
    private Node root;
    public void add(Node node){
        if(root==null){
            root=node;
        }else {
            root.add(node);
        }
    }
    public void infixOrder(){
        if(root!=null){
            root.infixOrder();
        }else {
            System.out.println("二叉排序树为空");
        }
    }
    public Node search(int value){
        if(root==null){
            return null;
        }else {
            return root.search(value);
        }
    }
    public Node searchParent(int value){
        if(root==null){
            return null;
        }else {
            return root.searchParent(value);
        }
    }
    public void delNode(int value){
        if(root==null){
            return;
        }else {
            Node targetNode = search(value);
            if(targetNode==null){
                return;
            }
            if(root.left==null&&root.right==null){
                root=null;
                return;
            }
            Node parent = searchParent(value);
            if(targetNode.left==null&&targetNode.right==null){
                if(parent.left!=null&&parent.left.value==value){
                    parent.left=null;
                }else if(parent.right!=null&&parent.right.value==value){
                    parent.right=null;
                }
            }else {
                if(targetNode.left!=null){
                    if(parent.left.value==value){
                        parent.left=targetNode.left;
                    }else {
                        parent.right=targetNode.left;
                    }
                }
            }
        }
    }
}
class Node{
    int value;
    Node left;
    Node right;

    public Node search(int value){
        if(value==this.value){
            return this;
        }else if(value<this.value){
            if(this.left==null){
                return null;
            }
            return this.left.search(value);
        }else {
            if(this.right==null){
                return null;
            }
            return this.right.search(value);
        }
    }

    public Node searchParent(int value){
        if((this.left!=null)&&this.left.value==value||(this.right!=null&&this.right.value==value)){
            return this;
        }else {
            if(value<this.value&&this.left!=null){
                return this.left.searchParent(value);
            }else if(value>=this.value&&this.right!=null){
                return this.right.searchParent(value);
            }else {
                return null;
            }
        }
    }


    @Override
    public String toString() {
        return "Node{" +
                "value=" + value +
                '}';
    }

    public Node(int value) {
        this.value = value;
    }
    //添加节点

    public void add(Node node){
        if(node==null){
            return;
        }
        if(node.value<this.value){
            if(this.left==null){
                this.left=node;
            }else {
                this.left.add(node);
            }
        }else {
            if(this.right==null){
                this.right=node;
            }else {
               this.right.add(node);
            }
        }
    }

    //中序遍历
    public void infixOrder(){
        if(this.left!=null){
            this.left.infixOrder();
        }
        System.out.println(this);
        if(this.right!=null){
            this.right.infixOrder();
        }
    }
}
